The present disclosure relates generally to medical devices. More particularly, it relates to thrombectomy devices for removing thrombus deposits from a space between a body valve and a wall of a body vessel.
Vascular disease affects a large proportion of individuals each year. One indication of the existence of this disease is the development of a blood clot in the vascular system, which if left untreated may result in deep vein thrombosis, embolisms, or ischemic. Thrombi within the vasculature can form as a result of a variety of causes, such as trauma, disease, surgery, stagnant blood, and foreign devices in the vasculature. These clots are usually comprised of an aggregated mixture of thrombus and fibrin. Typically, a thrombus present in an arterial blood vessel tends to migrate in the direction of flow from a large diameter artery to smaller diameter arteries. The thrombus continues to flow with the blood until it becomes lodged against the vessel wall and is unable to advance. In some instances, the thrombus partially or completely blocks blood flow through the artery thereby preventing blood from reaching the tissue disposed downstream of the thrombus. Denying blood flow for an extended period of time can result in damage or death of the tissue beyond the blockage. The result can be loss of toes or fingers, or even an entire limb in more severe circumstances. Moreover, thrombi in the venous system can migrate to the lungs and become a pulmonary embolus, which is usually fatal. In other instances, thrombi can migrate into the cerebral circulation and cause stroke and death.
Various known techniques for the removal of blood clots include both chemical and mechanical treatment. Chemical treatment typically involves the injection of lysine agents into the vessel near the blood clot to chemically attack, dissolve, and disperse the occlusion. In this technique, the lysine agent is brought into the proximate vicinity of the blood clot by injection through a cannula or other lumen.
The mechanical treatment of a blood clot typically involves the use of catheters having a rotary cutting head or other form of a rotor-stator homogenizing head. Examples of such rotary devices include rotating burr devices, devices with a rotating helical coil wire within a catheter, and recanalization catheters. Other mechanical devices utilize a balloon that is inflated in a vessel and then withdrawn to pull a clot into a conventional sheath. The sheath may then be withdrawn from the patient to remove the captured clot or the clot may be aspirated into the sheath and removed from the patient. Still other mechanical devices utilize a sharp point to pierce the occlusion to form a hole therethrough. In each of these cases, although the occlusion is reduced in size or a passageway is created, the residual thrombus/fibrin material resulting from the treatment remains within the vessel.
Although these treatment devices and methods may be adequate to remove the majority of a clot, they do not effectively remove the residual material formed during fragmentation of a blood clot or the accumulation of thrombus material disposed in the space between a body valve and a body vessel wall. Removal of such residual material and/or accumulated material is medically desirable. It is further necessary to ensure that this residual material and/or accumulated material does not migrate away from the site of the treatment to other parts of the vessel. Such migration could lead to serious complications, such as embolism, stroke, or heart attack.
Thus, what is needed is a device for removing the thrombus material from a space between a body valve and a body vessel wall. It would be desirable if such device is easy for a physician to use and compatible with existing thrombectomy methods.